The present invention relates to a safety device in the construction industry. Specifically, the invention relates to a safety guard attachable to shoring devices to protect the hands and fingers of workmen from being pinched or caught in a shoring device when it is being assembled, folded or collapsed.
Sound excavation safety practice and OSHA standards for safe trenching require that the side walls of trenches be supported or shored against collapse. The particular shoring requirements vary considerably with soil composition and trench size. With reference to FIG. 1, FIG. 2A and FIG. 2B, generally when excavating a trench 10 in stable soils, state and federal regulations require the trenches having a depth greater than approximately four to five feet be vertically shored to avoid exposing workers to the hazards of unshored trenches. Shoring devices 11 generally utilize vertical support members or shoring columns 12 which are held in place against the opposite trench walls by extendable hydraulic booms or jacks 14.
Generally known devices include opposite trench-engaging columns 12 which are connected to hydraulic jacks 14 at blocks 20 pivotally secured to shoring columns 12. In setting up such devices, the artisan lowers the shoring device into the trench causing it to unfold. The hydraulic jacks 14 are pressurized, usually using a portable source of hydraulic pressure such as a hand pump which feed into a nozzle 18 operably connected with the hydraulic jack 14. The opposite shoring columns 12 directly engage the side walls 16, or are attached to panels (not shown in FIG. 1) which support the excavation.
When it is desired to remove the shoring device, hydraulic pressure is relieved and the shoring device is pulled from the trench using a suitable tool or rope. The shoring device may then be collapsed or folded to a position with the shoring column 12 assuming a position adjacent one another. Collapsibility is permitted by the pivotal attachment of the opposite ends of the jacks 14 to mounting blocks 20 on the shoring columns.
A particular safety problem is that the mounting blocks 20 are usually located between flanges 22 extending from the shoring columns 12. When the shoring device is collapsed, the mounting block 20 pivots around a pin 21 (see for example FIGS. 4 and 6) and the worker, in lifting or grasping the shore, may inadvertently cause a finger to be pinched between the block 20 and the column 12 due to the scissor action of the components.
In order to protect workers, some shoring devices, known in the art, are equipped with a finger guard 24 (see for example FIG. 2B) which is screwed onto or pinned onto the shoring columns 12 to hold them in place using a screw or pin 26. However, such finger guards, while providing some degree of protection are not easily attached to or removed from existing shoring devices. Moreover, the holes permitting attachment to the shoring columns has the effect of weakening the columns which experience a considerable bending moment from the action of the hydraulic jacks. Furthermore, the system of attachment requiring holes to be formed in the shoring column leaves the artisan with little flexibility in locating his finger guard along the length of the column. The guards of confined to one location, determined by the position of the respective hole. And yet further, a shoring guard 24 of the kind seen in FIG. 2B is limited to the particular type of shoring column to which it is designed to be attached. This may give rise to the unwelcome experience in which an excavation contractor discovers that he has one type of shoring column, but different types of finger guards. What is needed in this regard is a universally applicable shoring guard that can be moved from one type of shoring column to another, allowing maximum economy and versatility.
Accordingly, it is a primary object of the present invention to provide an improved finger guard device for shoring devices which is safe, simple and easily attachable to a shoring device, and does not interfere with the structural integrity of the shoring device, and allows flexibility in locating the guard both along the length of the shoring device, and to other shoring devices of a different type.